I would go with the 5070. Thats just my opinion. If you are buying just for trainz, I daubt you will go over the 12gb of vram. I am using a rtx 5070ti, The 5070 can't be much slower than the 5070ti. Mine is blazing fast. You should be good for several years. The 5060 ti is on the pcie 5.0 speed at 8x. Not 4.0. I just don't think 4gb is worth the slower card with more vram. More vram doesn't always mean better card. Good luck.